1. Field of the Invention
The invention relates to a coaxial plug-and-socket connection, specifically for printed circuit boards.
2. Description of Related Art
In known coaxial plug-and-socket connectors of this kind, such as that described in German Patent No. DE 202 08 425.6, at least one socket forming an outer conductor and having an associated center conductor is usually fixed to each printed circuit board. The center conductor has, in this case, a contact pin, normally cylindrical, which can be plugged, in such a way as to be held in place resiliently, into a correspondingly shaped recess in the end-face of the center-conductor member of an adapter in the form of a sleeve-like plug-in coupler. The design is such that a defined air-gap is left between the outer-conductor socket and the end-face of the plug-in coupler.
Although coaxial plug-and-socket connectors of this kind normally meet the requirements they are called upon to meet sufficiently well, it has nevertheless been found that certain serious disadvantages do occur, doing so particularly at the high transmission frequencies which can be expected today, which may be as much as 60 GHz or more.
These disadvantages arise because even slight relative movements between the printed circuit boards which are connected together, both in the axial direction of the contact pins and also transversely thereto, cause an unwanted change in the contact zone between the contact pin of the center conductor and the center-conductor member of the female coupler. This in turn results in an unwanted change in the field resistance preset by the defined air-gap, which has a definite adverse effect on the quality of the electrical transmission.
These relative movements between the printed circuit boards, slight though they are, cannot be avoided and because of them there is no assurance, even with the known plug-and-socket connectors, that what is called repeatability of mating will remain the same, which is likewise considered a disadvantage.
Added to this, there is also the fact that the manufacture of coaxial plug-and-socket connectors of this kind involves a relatively high outlay in terms of time and money because there are always certain tolerances that have to be met in the connector, which has a commensurate effect on the cost of manufacture.
The object underlying the invention is therefore, in order to overcome the disadvantages described, to design the coaxial plug-and-socket connector of the generic kind in such a way that there is a crucial improvement in its repeatability of mating, particularly when the transmission frequencies are up to 60 GHz or more, and at the same time, while manufacture is considerably simplified and unwanted abrupt changes in the diameter of the contact pin are avoided, it is ensured that there is a contact zone which is good and remains equally good.